189 



shortly spinose on its inner side, 6 a very short lamella, 7-9 

 fairly elongate lamellae, each a little longer than joints 3-5 

 together. I can regard this structure only as a freak, either 

 in the individual or the species, unfitting it for description 

 without examination of more specimens. Rhopcea castanei- 

 pennis, Macl. (from North-West Australia) is incorrectly 

 placed in this genus, and I think it will require a new 

 generic name. There are two specimens (one of which is 

 labelled "type") which I have inspected in the Macleay 

 Museum ; but as I had not available for comparison examples 

 of the two new genera near Rhopcea that are diagnosed in 

 the following pages I do not venture to deal with it at pre- 

 sent. The structure of its labrum associates it with Para- 

 rhopcea, but the spurs of its hind tibiae are of the Rhopcea 

 type and the sculpture of the front face of its clypeus is 

 notably less rugulose (with much shorter and coarser pilo- 

 sity) than in Rhopcea and Para?hopcea, but nevertheless is 

 distinctly of the Rhopcea rather than the Lepidiota type. 

 It is clearly a very isolated form in the Melolonthides, and 

 its habitat is very remote from any from which known species 

 near Rhopcea have been reported, but probably the future 

 will bring to light other species from the same region con- 

 generic with it. 



The following table indicates characters by which the 

 males of the known species of Rhopcea can be dis- 

 tinguished : — 



A. Antenna] flabellum consists of 8 



laminae (7 of about equal length) ... magnioornis, Blackb. 

 AA. Antennal flabellum consists of 7 

 laminae (at least 6 of them long and 

 subequal). 

 B. Punctures of pronotum very close 

 throughout ; for the most part 

 confluent. 

 C. Joint 3 of antennae not longer than 

 its width at the apex. 

 D. Elytra, and dorsal surface of 

 pronotum, having only close 

 short pubescence. 

 E. Frothorax very strongly nar- 

 rowed in front, and with 

 sides very strongly rounded soror, Blackb. 

 EE. Prothorax not strongly nar- 

 rowed in front, and with 

 sides (viewed from above) 



lightly arched heterodactyla, Germ. 



DD. Elytra and whole surface of 

 pronotum sparsely set with 

 erect comparatively long hairs hirtuosa, Blackb. 

 CC. Joint 3 of antennae much more 



than twice as long as wide ... assimilis, Blackb. 



